Track frame stabilizer for tracklaying tractors



Dec. 24, 1935. E, A, JOHNSTON TRACK FRAME STABILIZER FOR TRACKLAYING TRACTORS Filed May 6, 1932 5 SheetsSheet 1 E. A, JOHNSTON fies. 24, 1935.

TRACK FRAME STABILIZER FOR TRACKLAYING TRACTORS Filed May 6, 1932 3 Sheets-Sheet 2 -I f a. 1 l.

E. A. JOHNSTON TRACK FRAME STABILIZER FOR TRACKLAYING TRACTORS I Dec. 24, 1935.

3 Sheets-Sheet 3 Filed May 6, 1932 Patented Dec. 24, 1935 UNITED STATES TRACK FRAME STABILIZER FOR TRACK- LAYING TRACTORS Edward A. Johnston Chicago, Ill., assignor to International Harvester Company, a corporation of New Jersey Application May 6, 1932, Serial No. 609,651

Claims.

This invention relates to track frame stabilizers for track-laying tractors.

The principal object of the invention is to provide a flexible, track-laying tractor with means 5 for maintaining the tracks against lateral movement with respect to each other and with respect to the main frame of the tractor. This object is accomplished by providing stabilizing means connected to the forward ends of the track frames and to the main frame of the tractor, said means being constructed to permit up-and-down movement of the track frames and to prevent movement of the track frames in a lateral direction with respect to the main frame of the tractor.

In the drawings:

Figure l is a general plan view of a tractor chassis embodying the invention with certain parts broken away and other parts removed to more clearly illustrate the invention;

Figure 2 is a side elevation of the same structure shown in Figure 1;

Figure 3 is a sectional view taken on the line 33 of Figure 1;

Figure 4 is an enlarged detail of the connection between the stabilizing member and the main frame of the tractor;

Figure 5 is a section taken on the line 5-5 of Figure 4; and

Figure 6 is a section taken on the line fi5 of Figure 4.

Referring to the drawings, the main frame it of the tractor is of a conventional construction except for the addition of the securing means for the stabilizer, to be hereinafter described. Driving means for the track H are provided at the rear of the tractor, said means being of any conventional construction. The track frames 12, positioned at the sides of the tractor, are pivoted to the main frame on a transverse axis. This construction has not been shown in detail as it is well known in the art. The axis of attachment is designated by the numeral IS. The front equalizer support M in the form of a spring, extends under the forward portion of the main frame and over the track frames. Said support is pivotally connected on a longitudinal axis to the main frame, as shown in Figure 3. Said support is also pivotally connected to the track frames by means enclosed in the housings 5 secured to the track frames. The particular construction of the housing l5 and the attaching means therein, is the subject-matter of the copending application, Serial No. 578,429 filed December 2, 1931.

It is to be understood that the construction above described is well known in the art and it is in connection with a track-laying tractor of the type described that the stabilizer of the present invention is to be applied.

In the operation of a tractor of this type, the

track frames at the sides of the main frame move up and down with respect to each other and with respect-to the main frame, the support it serving as an equalizer. By reason of the pivotal arrangement of said equalizer member, the upward pivotal -movement of one of the track frames It. will produce a corresponding downward move ment on the opposite track frame. In other words, the track frames will be able to accommodate themselves to the varying character of the road upon which they are traveling without dis-= turbing the position or equilibrium of the main frame or body of the tractor. It is necessary that the ends of the support be connected to the track frame by means which will permit lateral movement of the track frames with respect to the ends of the support. This is necessary because, as the spring rotates about its axis of attachment with the main frame, the lateral horizontal distance between its ends shortens. This movement has been provided for in numerous ways, such as by spring shackles of different types. In the particular embodiment of the invention illustrated, said movement is provided for by pivotally connecting the ends of the transverse support M on cylindrical attaching members it, as shown in Figure 6. Said members are arranged with their axes extending in transverse directions. The cylindrical attaching members are mounted in the housings I5 for limited lateral movement therein, whereby the necessary lateral movement of the ends of the support M with respect to the track frames, is obtained.

A member El, consisting of a body portion and two parallel and oppositely extending stub shafts i8 and I 9, is positioned at each side of the tractor to form the stabilizer connection between the main frame and the track frame. The members are exactly similar in construction except that one is left-handed with respect to the other. The shaft is rotatably extends through a bearing member 20 mounted on the track frame. Said shaft is provided with a shoulder 2| at its inner end of the bearing 29 and a thrust element 22 at the outer end to prevent lateral movement of the shaft and the member I l with respect to the track frame.

The member ll extends in a substantially horizontal position when the track frames are on the same level, as shown in Figure 2. The shaft I8 is positioned on the member [1 forwardly from the shaft l9.

Below the main frame at each side an integral boss or supporting bracket 23 is formed with a vertical face forattaching a housing 24. Said housing has a cover plate 25 secured thereto and is formed internally with two parallel spaced walls arranged in vertical longitudinally extending planes, one of said Walls being the inner surface of the cover plate 25. As best shown in Figure 5,

- end of the stabilizing member I1.

said cover plate is provided with a substantially centrally located opening in the form of a slot 26 extending in the longitudinal direction. The shaft I8 extends through the opening, said opening being slightly larger in the vertical dimen-" sion than the diameter of the shaft, and considerably longer in the fore and aft direction. A plate 21 is rigidly secured to the end of the shaft I8 and is mounted within the housing 24. Said plate is cylindrical in form and is of a thickness slightly less than the width of the space formed by the inner walls of the housing. The plate is also somewhat less in diameter than the diameter of the interior of the housing, whereby it may move freely within the limits defined by the interior' of the housing. A flexible shield 28 is secured to the plate 25 around the slot 26 and around the shaft I8 to form an oil-tight seal between said members while permitting rotation of the shaft with respect to the housing andthe fore and aft movement of translation.

By the construction above described, it will be understood that upon pivoting movement of the track frame I2 with respect to the main frame I of the tractor the bearing member 20 carried on the track frame will move up and down, thereby lifting and lowering the shaft I9 and the rear Said member will also be angularly moved with respect to the main frame, its movement being permitted by rotation of the plate 21 within the housing 24. It Will also be understood that due to the fact that the track frame I2 and the member I! are pivoted on different axes on the main frame, it will be necessary for one of the axes to move with respect to the other as the common axis, that is, the axis of the shaft I9 moves up and down. This movement is provided for by the slot 26, which is of a length sufficient to allow thefore and aft movement of the shaft I8 for the maximum angular displacement of the track frame. There is also sufficient clearance between the interior walls of the housing and the plate 21 to permit the fore and aft movement of translation required by said angular movement of the track frame with respect to the main frame. The shield 28 encloses the moving parts in such a manner that dust cannot enter and lubrication will not be affected. As the plate 21 cannot move laterally with respect to its housing and as the shaft I 9 cannot move laterally with respect to the bearing member 20 on the track frame, the stabilizer member I! prevents lateral movement of the track frame with respect to the main frame. The comparatively long length of the bearing 20 and the large area of the plate 21 give the stabilizing member sufficient strength to resist all side thrusts encountered in normal operation.

It is to be understood that applicanthas shown and described only a preferred embodiment of his improved stabilizing means for track-laying tractors andthat he claims as his invention all modifications falling within the scope of the appended claims.

What is claimed is:

1. In a track-laying tractor having a main frame, track frames pivotally connected on a transverse axis to the'rear of the main frame and a transverse front supportpivotally connected to the main frame and to thetrack frames, a track stabilizer at each side of the tractor consisting of a single connecting member, means for connecting said member to a track frame on a. transverse axis, and means for directly-connecting the member to the main frame for angular movement with respect thereto on a transverse axis and for limited movements of translation in the fore and aft directions.

2. In a track-laying tractor having a main frame, track frames pivotally connected on a transverse axis to the rear of the main frame, and a transverse front support pivotally connected to the main frame and to the track frames,

2. track stabilizer at each side of the tractor con- 10 sisting of a single member havingspaced oppositely extending stub shafts, one of said shafts being pivoted on a track frame on a transverse axis, and means for connecting the other shaft directly to the main frame for angular movement with respect thereto on a transverse axis and for limited movement of translation in the fore and aft directions.

3. In a track-laying tractor having a main frame, track frames pivotally connected on a transverse axis to the rear of the main frame, and a transverse front support pivotally connected to the main frame and to the track frames, a track frame stabilizer at each side of the tractor comprising a member having spaced oppositely extending stub shafts, one of said shafts being pivoted on a track frame on a transverse axis, and means for connecting the other shaft to the main frame for angular movement with respect thereto and for limited movement of trans- 3O lation in the fore and aft direction, said means consisting of a plate fixed to the end of the shaft in a substantially longitudinal vertical plane and means on the main frame to hold said plate for rotation with respect thereto and to permit limited longitudinal movement of the plate. i

4. In a track-laying tractor having a main frame, track frames pivotally connected on a transverse axis to the rear of the main frame, and a transverse front support pivotally connected to the main frame and to the track frames, 2. track frame stabilizer at each side of the tractor comprising a member having spaced oppositely extending stub shafts, one of said shafts being pivoted on a. track frame on a transverse axis, and means for connecting the other shaft to the main frame for angular movement with respect thereto and for limited movement of translation in the fore and aft direction, said means consisting of a housing secured to the main frame, a cover plate on said housing formed with an opening in the form of a longitudinally extending slot through which the shaft extends, a plate fixed to the end of the shaft within the housing for angular movement with respect thereto and for limited movement of translation in a longitudinal vertical plane.

5. In a track-laying tractor having a main frame, track frames pivotally connected on a transverse axis to the rear of the main frame and a transverse front support pivotally connected to the main frame and to the track frames,

a track stabilizer at each side of the tractor comprising a connecting member between the main frame and one of the track frames, means for pivotally connecting said member to one of the frames which it connects for angular movement with respect thereto on a transverse axis, and means for directly connecting the member to the other of said frames for angular movement with respect thereto on a transverse axis and for limited movements of translation in fore and aft directions.

EDWARD A. JOHNSTON. 

